Ravaggi A, Natoli G, Primi D, Albertini A, Levrero M, Cariani E
Consorzio per le Biotecnologie, Consiglio Nazionale delle Ricerche (CNR), School of Medicine, University of Brescia, Italy.
J Hepatol. 1994 Jun;20(6):833-6. doi: 10.1016/s0168-8278(05)80157-6.
The putative hepatitis C virus core protein has a predicted molecular weight of about 22 kD and contains two carboxy (COOH)-terminal hydrophobic domains. The cleavages generating the hepatitis C virus structural proteins (core, E1 and E2) are catalyzed by host signal peptidases. In the present study, we investigated the processing and intracellular localization of the hepatitis C virus core protein expressed in mammalian cells. Expression vectors encoding the entire core protein or COOH-terminal deletion mutants under the control of SV40 regulatory sequences were transfected in COS cells. Immunofluorescent staining with either polyclonal immunoglobulin or monoclonal anti-core antibodies showed that fragments containing the COOH-terminal hydrophobic stretch were retained in the cytoplasm of transfected cells, whereas truncated core proteins deleted of 28 or more residues were located in the nucleus. Our results suggest that a putative nuclear targeting sequence is contained in the first 40 residues of the core protein.
推测的丙型肝炎病毒核心蛋白预测分子量约为22 kD，含有两个羧基（COOH）末端疏水结构域。产生丙型肝炎病毒结构蛋白（核心、E1和E2）的切割由宿主信号肽酶催化。在本研究中，我们研究了在哺乳动物细胞中表达的丙型肝炎病毒核心蛋白的加工过程和细胞内定位。将编码完整核心蛋白或在SV40调控序列控制下的COOH末端缺失突变体的表达载体转染到COS细胞中。用多克隆免疫球蛋白或单克隆抗核心抗体进行免疫荧光染色显示，含有COOH末端疏水片段的片段保留在转染细胞的细胞质中，而缺失28个或更多残基的截短核心蛋白则位于细胞核中。我们的结果表明，核心蛋白的前40个残基中包含一个推测的核定位序列。
